(1) Field of the Invention
This invention relates to a spark intensifying device adaptable in a gasoline engine for automobiles, etc., in which a high-tension secondary current generated from an ignition coil is accumulated in a capacitor set at the head of a spark plug in the engine, and when the voltage of the discharging shaft at the end of the spark plug has risen to a predetermined value for discharge, the static electricity accumulated in said capacitor is discharged at one effort to produce strong sparks.
(2) Description of the Prior Art
In many of the latest antipollution cars, the engine power and acceleration performance are sacrified for coming up to the strict regulations on emission of noxious matters such as HC, CO and NOx in exhaust gas. Recently, use of a transistorized ignition system is prevalent in the engines employing a so-called lean gas combustion system or other like systems for improving the engine performance at acceleration and preventing mis-sparking. On the othe hand, the spark plug markers are making various attempts, such as changing the end configuration of the spark plug, for improving combustion efficiency.
An important and very difficult problem that arises in this connection is how to increase the high-voltage discharge current at the tip of the spark plug.
In the existing standard type automobiles which are not mounted with a full- or semi-transistorized system, the maximum voltage that is produced by the ignition coil is approximately 18 KV, and the discharge value attainable with the spark plug with discharging gap of about 0.8 mm by way of a plug cord is down to the order of 12 KV.
Although the secondary voltage generated by the ignition coil in the semi- or full-transistorized systems is amplified to the order of 40 KV, the discharge voltage at the tip of the spark plug with a discharging gap of about 1.1 drops to the level of 26 KV.
There is appearing on the market a plug cord which is so deviced as to lower resistance while minimizing current leakage in order to arrest voltage drop at the tip of the spark plug. Use of such plug cord, however, is not a decisive solution to the problems which are posed by the currently employed lean gas combustion system.